3,170 research outputs found
Conceptual fit: A criterion for COTS selection
COTS systems selection consists in evaluating the user requirements with respect to characteristics of candidate systems, using a set of criteria. One criterion that has received little attention is what we call conceptual fit. The criterion assesses the fit between the conceptual structure of the user requirements and that of a system. We evaluate the fit in terms of the existing misfits. We formally define the notion of conceptual misfit and we present a method that determines the conceptual misfits between the user requirements and a set of candidate systems. The method consists in defining a superschema, the mapping of the conceptual schemas of the candidate systems and of the user requirements to that superschema, and the automatic computation of the existing conceptual misfits. The method has been formalized in UML/OCL. We have conducted an exploratory experiment with the aim of evaluating the feasibility, difficulty and usefulness of the method, with positive results. We believe that the conceptual fit criterion could be taken into account by almost all existing COTS selection methods.Preprin
A universal ontology-based approach to data integration
One of the main problems in building data integration systems is that of semantic integration. It has been acknowledged that the problem would not exist if all systems were developed using the same global schema, but so far, such global schema has been considered unfeasible in practice. However, in our previous work, we have argued that given the current state-of-the-art, a global schema may be feasible now, and we have put forward a vision of a Universal Ontology (UO) that may be desirable, feasible, and viable. One of the reasons why the UO may be desirable is that it might solve the semantic integration problem. The objective of this paper is to show that indeed the UO could solve, or at least greatly alleviate, the semantic integration problem. We do so by presenting an approach to semantic integration based on the UO that requires much less effort than other approaches.Peer ReviewedPostprint (published version
CO2 and nutrient-driven changes across multiple levels of organization in zostera noltii ecosystems
Increasing evidence emphasizes that the effects of human impacts on ecosystems must be investigated using designs that incorporate the responses across levels of biological organization as well as the effects of multiple stressors. Here we implemented a mesocosm experiment to investigate how the individual and interactive effects of CO2 enrichment and eutrophication scale-up from changes in primary producers at the individual (biochemistry) or population level (production, reproduction, and/ or abundance) to higher levels of community (macroalgae abundance, herbivory, and global metabolism), and ecosystem organization (detritus release and carbon sink capacity). The responses of Zostera noltii seagrass meadows growing in low-and high-nutrient field conditions were compared. In both meadows, the expected CO2 benefits on Z. noltii leaf production were suppressed by epiphyte overgrowth, with no direct CO2 effect on plant biochemistry or population-level traits. Multi-level meadow response to nutrients was faster and stronger than to CO2. Nutrient enrichment promoted the nutritional quality of Z. noltii (high N, low C : N and phenolics), the growth of epiphytic pennate diatoms and purple bacteria, and shoot mortality. In the low-nutrient meadow, individual effects of CO2 and nutrients separately resulted in reduced carbon storage in the sediment, probably due to enhanced microbial degradation of more labile organic matter. These changes, however, had no effect on herbivory or on community metabolism. Interestingly, individual effects of CO2 or nutrient addition on epiphytes, shoot mortality, and carbon storage were attenuated when nutrients and CO2 acted simultaneously. This suggests CO2-induced benefits on eutrophic meadows. In the high-nutrient meadow, a striking shoot decline caused by amphipod overgrazing masked the response to CO2 and nutrient additions. Our results reveal that under future scenarios of CO2, the responses of seagrass ecosystems will be complex and context-dependent, being mediated by epiphyte overgrowth rather than by direct effects on plant biochemistry. Overall, we found that the responses of seagrass meadows to individual and interactive effects of CO2 and nutrient enrichment varied depending on interactions among species and connections between organization levels.European Regional Development Fund through the COMPETE; Portuguese funds through the FCT project [PEst-C/MAR/LA0015/2011]
EU-Rent car rentals specification
EU-Rent is a widely known case study being promoted as a basis for
demonstration of product capabilities. However, no in-depth case
analysis neither specification has been developed. Therefore, it was
considered interesting, useful and even necessary to develop a complete
study of the case, which would lead to its whole specification.
On the other hand, it was considered a good opportunity to test the
application of some proposals, such as alternate mechanisms to define
integrity constraints and derivation rules, as well as an alternative
approach to model events.Postprint (published version
Axioma d'elecció. Equivalències i aplicacions
Es tracta d'estudiar l'axioma d'elecció i alguns dels molts enunciats equivalents, entendre i explicar les demostracions de les equivalències sempre que l'argument estigui a l'abast d'un estudiant acabant el grau de matemà tiques, i estudiar també els principals resultats que s'obtenen aplicant aquest axioma i les seves demostracions
Crisi social, experiència individual, identitat cultural i acció col·lectiva
Aquest article és un breu resum dels principals aspectes tractats en el projecte de tesi doctoral –en procés de realització– on s’analitzen tant la crisi econòmica i social que s’ha produït en els últims anys com els discursos explicatius que s’han traslladat a l’opinió pública, i també, finalment, com aquests han estat llegits per la ciutadania i com l’experiència dels individus i la lectura que en fan han transformat els seus valors i actituds.Farem una breu anà lisi bibliogrà fica sobre dos dels aspectes claus tractats: en primer lloc, el concepte de Mediterrà nia com a oposat a Europa i carregat d’un simbolisme associat a estereotips negatius (irresponsabilitat, malbaratament, irracionalitat…), i en segon lloc, les principals transformacions socioeconòmiques anteriors i contemporà nies a la crisi financera actual. Ambdós elements, entenem, permeten contextualitzar el procés viscut, alhora que situen els punts de vista dels informants consultats al voltant d’aspectes de la seva identitat i de l’anà lisi de la realitat socioeconòmica; les opinions dels informants constitueixen el nucli de l’article
Representación de estructuras argumentativas mediante el análisis de redes sociales
Bajo el nombre de Análisis Reticular del Discurso (ARD) podemos englobar un conjunto muy amplio y diverso de tĂ©cnicas que pretenden representar los discursos como una red de significados. La idea es bien sencilla: las palabras, acciones, proposiciones… son nodos de un entramado lingĂĽĂstico que las relaciona, y que puede ser estudiado mediante el análisis de redes sociales (Lozares y otros, 2003). El artĂculo aborda una aproximaciĂłn al ARD desde la teorĂa de la argumentaciĂłn en la lengua (Anscombre y Ducrot, 1983), que introduce la nociĂłn relacional de topos (plural, topoi). Es posible representar la superposiciĂłn de todos los topoi identificados en una red discursiva que esquematiza sistemas cognitivo-ideolĂłgicos, potencial que contemplan ya los mismos autores de la teorĂa, aunque no llegan a desarrollar. El texto se presenta una propuesta metodolĂłgica en este sentido, y muestra los resultados de una aplicaciĂłn empĂrica al estudio de los discursos sobre la formaciĂłn y el empleo.Reticular Analysis of Discourse (ARD) refers to a large range of techniques that intend to represent the discourse as a network of meanings. The idea is well simple: the words and/or propositions are nodes of a linguistic network that relates them, and that can be studied by Social Network Analysis (Lozares et al, 2003). This text focus on ARD from theory of argumentation within language (Anscombre and Ducrot, 1983), which introduces the relational notion of topos (plural, topoi). It is possible to represent the globally of all the topoi identifed in a discursive network that schematizes cognitive/ideological systems, a possibility already contemplated, by authors, although not developed. This text presents a methodological proposal in this direction, and samples the results from an empirical application at the study of the discourses about formation employment
Tumors benignes vs. tumors malignes
Entenem com a tumor el creixement anòmal, per excĂ©s, d’una massa de cèl·lules determinades, que poden ser com les cèl·lules normals de l’organisme o bĂ© pot tractar-se de cèl·lules atĂpiques. La diferència essencial entre els tumors benignes i els malignes rau en la capacitat dels malignes d’escampar-se per tot el cos, per la qual cosa, el pronòstic d’aquests Ă©s, en principi, pitjor que el dels benignes. Aquesta afirmaciĂł pot no ser del tot certa, ja que pot donar-se el cas de tumors malignes amb baixa malignitat i de fĂ cil tractament i en l’altra banda tindrem els tumors benignes difĂcils de localitzar i de tractar i que poden ser força invalidants, com seran aquells que afectin a estructures de vital importĂ ncia (cor, cervell...).Mots clau: tumor, tumors benignes, tumors malignes. ResumenSe denomina tumor al crecimiento anĂłmalo, por exceso, de una masa de cĂ©lulas determinadas, que pueden ser como las del propio organismo o bien tratarse de cĂ©lulas atĂpicas. La diferencia esencial entre tumor benigno y maligno estriba en la capacidad de los malignos de extenderse por todo el cuerpo, por lo que el pronĂłstico de Ă©stos, en principio, es peor que en el caso de los benignos. Esta afirmaciĂłn puede, en determinadas ocasiones, ser discutida, ya que puede darse el caso de tumores malignos con malignidad baja y tratamiento sencillo y, por otro lado, tumores benignos difĂciles de localizar y tratar que pueden ser altamente invalidantes, como son los que afectan a estructuras de importancia vital (corazĂłn, cerebro...). Palavras clave: tumor, tumores benignos, tumores malignos.AbstractTumor is the name of an abnormal growth, by excess, of a mass of certain cells, which can be as the body itself or being atypical cells. The essential difference between benign and malignant tumor lies in the ability of the malignant ones to spread throughout the body, so the prognosis of these, in principle, is worse than in the case of the benign ones. This statement can, on occasion, be discussed, as it may be the case of malignant tumors with low malignancy and simple treatment and on the other hand we have benign tumors difficult to locate and treat that can be highly disabling, as they will be affecting vital structures (heart, brain...) Key words: tumor, benign tumor, malignant tumor
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